(1) Field of the Invention
This invention relates to anti-burglary devices and more particularly to the provision in a convenient retrofitable form of a reinforcing means for the doorjambs of residences and the like.
(2) Discussion of the Prior Art
One of the prime methods of entering residences and other buildings by burglars and strong-arm men, not to say law enforcement personnel who wish to take the occupants by surprise, is a simple kick to the door near the bolt or latch. Since the striker plate into which the latch of the door slides is usually merely bolted to the doorjamb about a routed-out orifice in the doorjamb, a well placed kick will usually break the striker plate from the doorjamb fracturing the jamb in the process and allowing the door to fly open. This is as true with modern steel-cased doors as with older doors, since the striker plate is positioned invariably along the edge of the jamb with only a minimum of wood about the latch opening which the striker plate is supposed to reinforce.
A great number of arrangements have been invented in the past for reinforcing the doorjamb in the striker plate area, many of which have been relatively effective, but none of which have achieved any substantial use due to impracticalities in their design and implementation.
Among the arrangements that have been tried and found wanting due to impracticality, even though effective in reinforcing the door, are those disclosed in the following patents:
U.S. Pat. No. 3,338,008 issued Aug. 29, 1967 to S. Sklar discloses a so-called knock-down door buck construction comprising a method of forming and installing a doorjamb and head piece. The arrangement is comprised of preformed pieces and includes metal clips which are attached to the frame of the door and incorporate flanges which extend outwardly into grooves in the trim strips on the side of the door frame.
U.S. Pat. No. 3,767,245 issued Oct. 23, 1973 to John N. Keefe discloses a reinforced striker plate for a doorjamb. The striker plate of Keefe has an elongated extension along one side which may be mounted flush against the doorjamb under the door's stop striping. The arrangement provides essentially a reinforced striker plate.
U.S. Pat. No. 3,815,945 issued Jun. 11, 1974 to E. R. Lamphere discloses a combined reinforcing plate and striker plate in the form of an expanded or reinforced striker plate having a shape arranged to extend over a fairly large portion of a doorjamb and an integral door stop upon the doorjamb. The expanded combination striker plate and reinforcing plate are held against the doorjamb by means of screws extending completely through the doorjamb and into the studding of the door frame. The reinforced striker plate and reinforcing plate preferably has small flanges along the edges to aid in engaging with the doorjamb.
U.S. Pat. No. 3,918,207 issued Nov. 11, 1975 to P. Aliotta discloses a doorjamb reinforcing arrangement in which the jamb is backed by a metal plate which may extend essentially across the entire rear of the jamb and, if necessary, from one end to the other of the jamb. The metal plate is provided with spaced fastening holes and may be fastened either by screws or bolt-type fastenings which pass either from the rear of the plate through the pre-drilled holes in the plate into the back of the doorjamb or alternatively by bolts which pass from the front of the doorjamb through the jamb into and through the reinforcing plate on the rear. A jamb reinforcing plate is also provided with a flange along one side to reinforce the side of the jamb closest to the one side to reinforce the side of the jamb closest to the striker plate hole. Either the side of the jamb or the back of the trim strips must be routed out on the side where the flange is provided in order to provide a tight fitting connection. The practicality of the Aliotta plate is consequently severely compromised by the necessity for performing operations which are inconvenient and difficult to carry out in the field.
U.S. Pat. No. 3,963,269 issued Jun. 15, 1976 to S. R. Rosenberg discloses a door strengthening arrangement including a metal casing which passes around the outer portion of a doorjamb, including a door stop arrangement. A special slotted reinforcing plate is mounted directly upon the door and when the door is closed, an extension from the striker plate passes through the slotted member on the door and aids in preventing the door and the doorjamb from being sprung apart by means of a crowbar or the like. One small section of the expanded striker plate is designed to extend around the front of the doorjamb and interlock with the back of the jamb.
U.S. Pat. No. 3,967,845 issued Jul. 6, 1976 to B. C. Governale discloses the use of an expanded reinforcing plate positioned over the latch orifice to basically reinforce the front of the doorjamb about the latch orifice. A conventional striker plate is mounted directly over the reinforcing plate and substantially obscures the reinforcing plate from outside view. The reinforcing plate is therefore substantially concealed from view both by being under the conventional striker plate and also having its expanded section on one side hidden under the weather stripping which normally is provided along the jamb adjacent to the doorstop.
U.S. Pat. No. 4,057,275 issued Nov. 8, 1977 to L. J. La Beaud discloses an elongated metal reinforcing plate fastened to the back of a wooden doorjamb to reinforce the doorjamb opposite to a conventional striker plate. The La Beaud plate has angled teeth which extend into the doorjamb from the back. A flange is provided on one side of the La Beaud reinforcing plate forming an angled lip extending along one side of the plate. This lip is arranged to catch behind the latch of the door and extends on both of the latch sides in an opening or slot in the doorjamb.
U.S. Pat. No. 4,174,862 issued Nov. 20, 1979 to C. F. Shane discloses a door frame reinforcing plate in which a metal plate is provided on the back of the doorjamb. The lock bolt extends completely through the jamb and through an orifice in the metal plate. A bent-over section of the reinforcing plate also is extended over the outside end of the doorjamb. In a more preferred embodiment, furthermore, an additional extension of the metal plate is bent around the back of the two by fours (2".times.4"s) of the door frame so that the metal reinforcing plate takes the form of a U-shaped plate which almost completely surrounds the timbers of the door frame.
U.S. Pat. No. 4,195,870 issued Apr. 1, 1980 to J. Percoco discloses a striker plate reinforcing arrangement. There are several embodiments of the Percoco device including the use of a block-type striker plate providing a heavier section into which the latch bolt extends. Such block-type striker plate is attached in various ways to other portions of the door.
U.S. Pat. No. 4,295,299 issued Oct. 20, 1981 to D. M. Nelson discloses a J-shaped reinforcing plate having the major arm on the back of the doorjamb and the minor arm on the front of the doorjamb with a connecting web extending along the outer end of the doorjamb. The reinforcing plate is applied to the doorjamb by removing the outer trim and apparently a groove is also provided in the front of the doorjamb also to accommodate the end of the minor arm of the plate section. No space is shown behind the doorjamb into which the rear portion of the reinforcing plate fits. The Nelson patent shows a fastening in the form of a nail passing from the front of the doorjamb through the doorjamb into and through the major arm of the reinforcing plate extending along the back of the jamb. It is not quite clear how the nail is forced into the plate. Nelson does constitute a broad disclosure of having a reinforcing plate extending along the rear of a doorjamb and a fastening extending from the front of the doorjamb through the plate to hold it in place against one of the framing two by fours (2".times.4"s) of the door frame.
U.S. Pat. No. 4,383,709 issued May 17, 1983 to T. O. Ronan discloses a striker plate which in one embodiment completely ensheaths a section of the outer portion of a doorjamb. The main thrust of the Ronan patent is to provide a blocking plate adjacent to the lock to prevent tools from being inserted from the outside to spring the bolt.
U.S. Pat. No. 4,416,087 issued Nov. 22, 1983 to P. K. Ghatak discloses a reinforcing plate mounted along the edge of a doorjamb to reinforce such jamb against fracture by a sharp kick or the like. Long bolts are shown extending from the heavy reinforcing plate longitudinally across the doorjamb into a bolt or nut opening near the opposite side of the doorjamb. Ghatak indicates his reinforcing method very effectively reinforces the doorjamb against the type of force which is usually used to kick open a door.
U.S. Pat. No. 4,684,160 issued Aug. 4, 1987 to G. J. Nelson discloses a reinforcing plate for use on the back of a doorjamb in conjunction with the usual striker plate on the front of the doorjamb. The reinforcing plate is designed to be attached to the frame members of the doorjamb and has the further elaboration of having a reinforced chute or column passing through the doorjamb in the vicinity of the striker plate which reinforced chute or column the latch bolt enters to provide a secure locking arrangement.
U.S. Pat. No. 4,717,185 issued Jan. 5, 1988 to R. A. Hartley discloses a combined striker plate and reinforcing plate which has side extensions extending inwardly along the sides of the two by four (2".times.4") framing members of the door frame. A forward extension from the striker plate surface also serves to reinforce the door stop of the door. Hartley specifically discloses that his arrangement is designed for new construction where the combined striker plate and reinforcing plate can be conveniently mounted on the original door frame.
U.S. Pat. No. 4,770,452 issued Sep. 13, 1988 to R. W. Petree discloses a reinforcement plate inserted into a groove in the doorjamb to reinforce such doorjamb. The plate is secured also directly to the framing members by a long threaded connector. The reinforcing plate, which is inset into a routed out portion of the doorjamb, is fairly long so it reinforces a large portion of the doorjamb. An ordinary striker plate is normally used on the outside of the doorjamb. Petree makes a point of the fact that his reinforcing plate can be retrofitted into existing structures. Petree states that in his invention only the outer doorjamb is removed and the security plate is installed into a groove routed out in the doorjamb without direct engagement or modification of any of the underlying support studs in the wall about the door frame.
U.S. Pat. No. 4,802,701 issued Feb. 7, 1989 to G. S. Mazie discloses a reinforcement plate for a lock which plate is installed behind the doorjamb. The reinforcing plate has a groove in it which receives a right angle bend on the doorjamb through the groove in the reinforcing plate and into a groove formed in the underlying frame of the door. Various screw fastenings may be used to mount the reinforcing plate directly upon the two by four (2".times.4") frame members of the door and a transverse screw member may be used to secure the right angled bent portion of the special striker plate in the groove.
U.S. Pat. No. 4,854,621 issued Aug. 8, 1989 to R. L. Baldwin discloses a combined striker plate and reinforcing plate arrangement in which an extended portion of the striker plate is bent into a "U" shape which passes about the doorjamb to basically reinforce the jamb itself. The arrangement is somewhat analogous to the Shane arrangement in which a plate passes across the back of the doorjamb and then is bent around the beams in the door frame rather than about the doorjamb itself. Baldwin has a further preferred arrangement comprising an angled plate arranged to be secured to the door frame itself and extend along the edge of the door frame over the plate extending around the back of the jamb. The jamb plate, in this way, is held securely to the door frame. Baldwin discloses he can also use the U-shaped striker plate alone without the additional security of the angled plate which normally holds the striker plate to the door frame members themselves. In such simplified embodiment, as noted above, the arrangement would appear to be primarily a reinforcement of the doorjamb. Baldwin discloses his arrangement is relatively easy to install. In new buildings, the U-shaped striker member and the angled tie plate can be positioned prior to attachment of the wooden trim or molding in the doorway. In existing doors, on the other hand, the existing striker plate is first removed and the door trim or molding is removed so that the striker plate member can be placed around the inner edge of the doorjamb while the tie plate member is hooked over the outside of the wall next to the doorway so that one leg extends between the door frame and the arm of the striker plate. The door trim molding is then secured to the doorway by screws to anchor the two members together.
U.S. Pat. No. 4,865,370 issued Sep. 12, 1989 to C. E. Francis discloses a boxed-in reinforced striker plate orifice. The reinforced boxing is attached to an anchor plate "preferably secured by long screws extending through the jamb into the trimmer stud". The reinforced striker bolt receiving chamber, referred to as an "anchor pocket", extends from the anchor plate side of the doorjamb forming an orifice in the jamb into which the deadbolt is extended. It is said that forceful entry is prevented since the anchor plate strengthens the doorjamb, "thus giving a very strong structural combination which can resist a rather strong splitting force caused by an attempted forceable entry". Francis uses shims in FIG. 7 and in FIG. 9 to retain the anchor plates against the rear of the jamb, evidently while a screw is turned into and through the reinforcing plate. In FIG. 8, the reinforcing plate is shown with a series of orifices for allowing passage of the screws through the plate.
U.S. Pat. No. 5,003,727 issued Apr. 2, 1991 to E. Watten discloses the use of a direct reinforcement of a striker plate by removing or mortising out a portion of the doorjamb under the striker plate and inserting into such portion a metal reinforcing element which may be a bent-over portion of a backing plate or a metal piece welded onto a backing plate which extends along the rear portion of the doorjamb. The reinforcing or backing plate on the back of the doorjamb is shown in FIGS. 4a and 4b as being secured to the jamb either by helical screws extending from the rear into the back of the jamb or from the front of the jamb through the reinforcing plate into the door opening.
While there has been broad recognition, therefore, that some practical means for reinforcing doorjambs against fracture due to kicks and the like intended to either spring open the door or to fracture the doorjamb and allow the door to swing open, would be desirable, such arrangements as have been tried have not proved to be really practical and consequently have been used little, if at all. In particular, the prior art has not embodied a reinforcing arrangement which can be easily mounted by relatively unskilled labor on either old installations of doors or new installations of doors and has not been sufficiently practical to encourage those in the art to provide the reinforcing means as a standard in house construction. Nor has there been an arrangement or method that could be retrofitted to existing door assemblies by relatively unskilled labor such as the usual homeowner.
There has been a clear need, therefore, for a simple, practical method and means for reinforcing the doorjambs of both existing buildings and new buildings to prevent the door from being broken open relatively easily by exposure to sharp blows such as may be delivered by a swift kick or other forceful entry-inducing force.